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+--- Thread: 870 0482 code, low boost (/showthread.php?tid=9895)
870 0482 code, low boost - DCtruckin - 01-10-2025
2005 cm870 cpl 8520(demandated via running rough 475hp tune) had 1 occurance, and inactive now code 0482 for low fuel pressure. On insite it showed 249.7 psi @ idle, and 262.3 psi @ about 1400 rpms. also, its never really been able to boost over 32 psi. I thought these things will go 38-40 psi? truck always seams sluggish and feels like you gotta drive the hell out of it to get it to move. Is this normal to have to floor board these things all day? Ive heard the 870 is one of the best ones to have as far as ISX goes, im not impressed with mine.
Ive also looked all over the web for info regarding HP/TQ ratings for different CM870 CPL #'s and have had no luck. What are the ratings for 8518,8519, & 8520?
RE: 870 0482 code, low boost - marek4792 - 01-10-2025
The air control valve box on these are known to be garbage even Cummins redesigned them recently.
RE: 870 0482 code, low boost - Rawze - 01-10-2025
If the vehicle is sluggish then it could be engine, but also it might be that you have too tall of rear ends in it for the application.
870's are a decent engine, and yes, they are naturally a bit slower on the up-take, especially at lower rpms, compared to anything more modern due to turbo lag, etc..
... Use the CT software to monitor the fuel control state to see if it is allowing full fueling at 100% loads. that and/or if you still don't think its making its advertised HP then have it dyno'ed/checked.
info: http://rawze.com/forums/showthread.php?tid=6641&pid=58693#pid58693
Also, at 475 HP, it should be cresting at about about 35-36~ish psi boost or so. It only takes 37 (38 max allowed) psi boost to make 600+ HP.
Many factors can make for lower (or incorrect) boost, including improper delete programming, clogged muffler, cac leaks, controller going bad, control arm hanging up, etc.etcv.etc.
If 'RR' did the programming, then that part should be ok.. as he knows the 870's very well... but if it is suspect, then monitoring fuel control state and other settings, as mentioned above, would reveal it.
This thread may also help...
http://rawze.com/forums/showthread.php?tid=6248&pid=54418#pid54418
and NO.. you should NOT be jumping CPL's and trying to use alternate programs in it.. that is a fast track to tearing something up. Have 'RR' simply change the power level .. Tier 2 CM870 will handle about 525HP, and about 1790 trq. .. maybe 1820 trq max. before those mid-tier injectors start getting hotter and wearing out sooner.
RE: 870 0482 code, low boost - DCtruckin - 01-11-2025
(01-10-2025 )marek4792 Wrote: The air control valve box on these are known to be garbage even Cummins redesigned them recently.
everything in the turbo system is within 2 years old, from the air line to the box, the box, stainless line to turbo, turbo, all replaced. its also a recon long block with 125k miles, pretty fresh motor
RE: 870 0482 code, low boost - DCtruckin - 01-11-2025
(01-10-2025 )Rawze Wrote: If the vehicle is sluggish then it could be engine, but also it might be that you have too tall of rear ends in it for the application.
870's are a decent engine, and yes, they are naturally a bit slower on the up-take, especially at lower rpms, compared to anything more modern due to turbo lag, etc..
... Use the CT software to monitor the fuel control state to see if it is allowing full fueling at 100% loads. that and/or if you still don't think its making its advertised HP then have it dyno'ed/checked.
info: http://rawze.com/forums/showthread.php?tid=6641&pid=58693#pid58693
Also, at 475 HP, it should be cresting at about about 35-36~ish psi boost or so. It only takes 37 (38 max allowed) psi boost to make 600+ HP.
Many factors can make for lower (or incorrect) boost, including improper delete programming, clogged muffler, cac leaks, controller going bad, control arm hanging up, etc.etcv.etc.
If 'RR' did the programming, then that part should be ok.. as he knows the 870's very well... but if it is suspect, then monitoring fuel control state and other settings, as mentioned above, would reveal it.
This thread may also help...
http://rawze.com/forums/showthread.php?tid=6248&pid=54418#pid54418
and NO.. you should NOT be jumping CPL's and trying to use alternate programs in it.. that is a fast track to tearing something up. Have 'RR' simply change the power level .. Tier 2 CM870 will handle about 525HP, and about 1790 trq. .. maybe 1820 trq max. before those mid-tier injectors start getting hotter and wearing out sooner.
The motor is self is a Recon long block, about 125k miles on it is all. its got 3.90 rears which is perfect for the application.
Would I use the CT while driving the truck or idle?
The whole turbo system is newer(see post above)
By no means am I trying to jump CPL'S I was just curious since every other ISX model CPL is listed somewhere on the web with that info. What would you think the 8520 would be safe power level? Im seriously about to make the EGR work properly again and take it directly to Cummins. But ill try these things as mentioned first.
RE: 870 0482 code, low boost - marek4792 - 01-11-2025
(01-11-2025 )DCtruckin Wrote:This update is within the last few months, they do fail without outright saying it's broke. Either this is your issue or your exhaust and boost pressure sensors are failing "in range".(01-10-2025 )marek4792 Wrote: The air control valve box on these are known to be garbage even Cummins redesigned them recently.
everything in the turbo system is within 2 years old, from the air line to the box, the box, stainless line to turbo, turbo, all replaced. its also a recon long block with 125k miles, pretty fresh motor
[attachment=9711]
[attachment=9712]
RE: 870 0482 code, low boost - DCtruckin - 01-12-2025
(01-11-2025 )marek4792 Wrote:(01-11-2025 )DCtruckin Wrote:This update is within the last few months, they do fail without outright saying it's broke. Either this is your issue or your exhaust and boost pressure sensors are failing "in range".(01-10-2025 )marek4792 Wrote: The air control valve box on these are known to be garbage even Cummins redesigned them recently.
everything in the turbo system is within 2 years old, from the air line to the box, the box, stainless line to turbo, turbo, all replaced. its also a recon long block with 125k miles, pretty fresh motor
interesting, good to know. Is that a direct from Cummins part? How could I test and check my exhaust and boost pressure sensors?
RE: 870 0482 code, low boost - marek4792 - 01-13-2025
Yup all oem Cummins TSB#240193. Exhaust pressure is checked key on engine off and should closely match the barometric pressure if either one hasnt failed. Boost is checked with shop air and a gauge like you're looking for a boost leak.